Element for recording photographic images



p 1951 A. B. JENNINGS ETAL 2,567,712

ELEMENT FOR RECORDING PHOTOGRAPHIC IMAGES Filed June 7, 1945 GELATIN CONTAINING INERTSILVER PARTICLES. TRANSPARENT SUPPORT.

GELATINHNERT SILVER PARTICLES +MAGENTA COLOR FORMEIH {GREEN S ENSITIZING DYE.

CLEAR GELATIN.

GELATIN +INERT SILVER PARTICLES +E LUE GREEN COLOR FORMER+ GREEN-BLIND-RED SENSITIZING DYE.

TRANSPARENT SUPPORT l e I CLEAR GELATIN.

GELATIN+INERT SILVER PARTICLES +GREEN-BLIND RED SENSITIZING DYE.

TRANSPARENT BASE.

GELATIN SILVER BROMIDE EMULSION I'MAGENTA COLOR FORMER.

,IMIIIIIIIIIII:

Andrewflradslzmnfenm g Qllls Tl vjlwrdM g INI/ENTORS A ATTORNEY GELATIN SILVER BROMIDE EMULSION +BLUE GREEN COLOR FORMER.

Patented Sept. 11, 1951 ELEMENT FOR RECORDING PHOTOGRAPHIC IMAGES Andrew Bradshaw Jennings, New Brunswick, and Otis Willard Murray, Fords, N. J., assignors to E. I. du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware Application June 7, 1945, Serial No. 598,126

9 Claims.

This invention relates to photography and more particularly to elements for recording photographic images that are initially inert to light. Still more particularly it relates to photographic elements such as films, plates, and papers that have layers which are inert to light but can readily be converted to light-sensitive silver halide layers which are sensitive in the blue region of the spectrum and have a range of extra sensitivity in the green or red regions of the spectrum. The invention also relates to processes of making and using such elements.

An object of the invention is to provide the art with new and useful elements for recording photographic images. Another object is to provide stable, economical photographic materials or elements which are not affected by light until they are ready for use. Another object is to provide new multilayer elements for color photography which are normally insensitive to light but can readily be converted to yield normal light-sensitive optically sensitized layers. Still more objects will be apparent from the description of the invention.

In its broader aspects the invention involves the preparation and use of photographic elements which consist of a base or support which carries at least one layer composed of a hydrophilic colloid that has dispersed therethrough finely divided silver and a small amount of an optical sensitizing dye. The layer may also contain a. color former. When a hydrophilic color former is used this may serve as a binding agent for the silver and also for forming color by coupling in a color coupling photographic development step.

The elements can be made by developing an exposed silver halide colloid-emulsion in a vigorous photographic developing solution and then washing to remove all traces of the developing agents. The emulsion can then be melted or dissolved in a suitable solvent, an optical sensitizing dye added and the resulting coating solution coated onto a suitable support and dried. The resulting element is substantially inert to light and can be safely handled in ordinary diffused daylight and even in sunlight without any deleterious efifect. Color forming elements can be made by adding a color former to the composition. This may be advantageously done at the time the optical sensitizing dye is added. However, it may be added to the original silver halide emulsion provided a non-color coupling developing agent is used in the reduction of the silver halide to silver particles.

2 The elements just described can be converted into a light-sensitive element prior to use by treating the-layer of finely divided, inert, silver particles in an aqueous bleach bath containing an oxidizing agent, e. g., ammonium persulfate and a. soluble halide salt, e. g., sodium bromide, potassium bromide, ammonium bromide, and the corresponding chlorides and iodides, in the absence of actinic light. After bleaching the element may then be washed and dried. It should then be kept under conditions of darkness or free from actinic radiations until used. The elements can be used in the same manner as the ordinary light-sensitive elements.

Multilayer color films constitute the preferred aspect of the invention. These films have at least two layers containing an immobile or nondifiusing color former and at least one layer containing finely divided particles of inert silver and an optical sensitizing dye. Various types of films containing such layers obviously can be made by those skilled in the art. One type, for example, may consist of a support bearing two silver halide emulsion layers which are sensitive to different primary colors of the visible spectrum and contain non-diffusing color formers that yield quinoneimine or azomethine dyes complementary in color to the utilized sensitivity of the layers and a third layer containing finely divided particles of inert silver and an optical sensitizing dye which extends the sensitivity of the layer to a still difierent primary color region of the visible spectrum.

Another type may consist of a support and three layers each composed of a hydrophilic colloid containing finely divided particles of inert silver, an optical sensitizing dye which extends the sensitivity of light-sensitive silver halides to a different primary color region of the visible spectrum and a non-diffusing color former which yields a quinoneimine or azomethine dye complementary in color to the utilized sensitivity of the layer. These elements may contain a yellow filter layer or stratum between the blue sensitized layer and the green and red sensitized layers. The layer which is sensitive to blue light after bleaching need not contain an added optical sensitizing dye if its acquired sensitivity is satisfactory.

Separator layers may be placed between the color yielding layers to prevent any bleeding of color formers. Various types of hydrophilic colloids both of natural and synthetic type can be used, such as gelatin, tanned gelatin, hardened polyvinyl alcohol, hydroxyl color forming poly- 3 mers, e. g., the polyvinyl acetals of U. S. Patents 2,310,943 and 2,320,422, etc.

The invention will be further illustrated in the accompanying drawing and in the following examples.

Eatample I 2,4-diaminophenol HCl grams 5.0 NaOH do 1.0 KBr do 1.0 Na2SO3 do 15 Water ccs 1000 After development, the shredded material is fixed in'the following:

Sodium thiosulfate grams 20 Water to ccs 100 and then washed to remove any soluble impurities. After washing, the shreds are melted and a dimeric sensitizing .dye of the type described in Example I of Wilson U. S. application Serial No. 487,849, new U. S. Patent 2,425,773, is added in an amount of .02 part per 1000 parts of developed emulsion. The emulsion is then coated onto a suitable transparent film support I in the conventional manner to form layer 2 having a thickness similar to a gelatino-silver halide layer. The resulting element (shown in Fig. l of the drawing) is inert to light and is not deleteriously affected by prolonged exposure to diffused daylight. When it became desirable to use the element it was bleached in darkness 1 minute in the following solution:

Ammonium persulfate grams 100 KBr do 5 Water to liter 1 The film was washed 10 minutes, bathed 5 minutes in 5% sodium bisulfite to eliminate oxidizing agents, washed minutes and dried. Exposure was made to a No. 2 photofiood at a distance of 24 inches for seconds and then developed in a developer of the following composition:

Grams p-Methylaminophenol. H2SO4 2.5 Sodium sulfite, anhydrous 75.0 I-Iydroquinone 3.0 Borax 5.0 Water 975.0

for 5 minutes to yield a normal silver image. Exposure through a light filter transmitting light between 500 and 600 millimicrons showed that the film has excellent grain and speed. Exposure through a light filter transmitting light of wave lengths above 580 millimicrons gave no evidence of red sensitivity.

Example II A film similar to that described in Example I is made by substituting for the sensitizing dye thereof 1,1'-diethyl-2,4-carbocyanine iodide.

The resulting element is exposed and processed after the manner described in Example I and.

evidences high blue and red sensitivity with no green sensitivity.

Example III A film similar to that described in Example I is prepared in the manner described in that example except that 1 part of a methylene-bispyrazolone described in U. S. Patent 2,294,909 per parts of developed emulsion is added at the same time the dye is added. The coating is carried out in daylight in the usual manner on a transparent support. The film is then bleached in darkness for 1 minute in the solution of Example I. After drying it is exposed and then developed in:

Diethyl paraphenylene diamine HCl grams 3 NazCOs (anhydrous) d0 30 KBr do 1 NazSOs do 5 Water to liter 1 which gives a strong magenta image. Sensitometric tests showed excellent green speed.

Example IV A film similar to that described in Example II is made by substituting for the magenta color former, 4,4'-bis- (1 naphthol 2 sulfonamidophenyl) ether prepared by reacting l-carbethoxynaphthol-sulfonyl chloride-2 with 4,4-bis(aminophenyl) ether as described in Jennings U. S. application Serial No. 483,333, now Patent No. 2,395,484, in an amount of 10 grams per kilogram of inert silver emulsion. The resulting element is exposed and color developed as in Example III and yields a strong blue-green image in situ with a silver image. After removal of the silver and silver salts with Farmers reducer a dye image remains.

Example V A multilayer film as shown in Fig. 2 is prepared by coating onto a cellulose acetate film 3 a gelatin dispersion of finely divided inert silver containing as a green blind red sensitizing dye 3,3-diethyl thiadicarbocyanine iodide and 1-oxy-2-naphthoic-plauryldodecy1 anilide as a blue-green color former to form layer 4, a gelatin separator layer 5 is coated on the latter coloryielding layer upon which is coated a gelatin dispersion of inert silver containing erythrosine and a methylene-bis-pyrazolone described in U. S. Patent 2,294,909 as a magneta color former to form layer 6.

The gelatin-silver dispersions are made by preparing a gelatino-silver halide emulsion containin the sensitizing dye and color former, extruding it through a perforated die to form noodles about one-eighth of an inch in diameter and cut to one inch lengths. The noodles are exposed to light and developed in a solution of the composition:

2,4-diaminophenol HCl grams 5.0 NaOH do 1.5 NazSOs dO 25.0 Water to liter 1 The noodles are then bleached in a solution a described in Example I, Washed, liquefied and prepared for coating as above described.

After bleaching and processing as indicated under Example III, layer 4 was exposed to red to a suitable separation negative. Layer 6 was exposed to green to an appropriate negative. Development in:

2-amino-5-diethylamino toluene hydrochloand subsequent bleaching and fixing yielded a strong two-color dye image.

Example VI The black and white element described in Example I was bleached in the usual manner, exposed and developed in the following developer to give a magenta image:

Diethyl paraphenylene diamine HCl grams NaaCOa 0---- 2 Meta-aminophenylmethylpyrazolone do HMi- NIQ'IN KBr do Na2SO3 do.. Water to liter In place of the pyrazolone, acetoacetanilide was employed to give a yellow image and 2,4- dichloronaphthol to give a blue-green image.

Example VII A cellulose acetate film base 1 is coated on one side with a gelatino-silver bromide emulsion containing as a magenta color former 4,4'-bis- (3"methylpyrazolonyl 1") biphenyl to form layer B, on the other side of the base is coated a gelatin dispersion of inert silver containing as a green blind red sensitizer kryptocyanine to form layer 9, a. stratum ill of clear gelatin is coated on the latter layer on which is coated a gelatino-silver halide emulsion containing the salicylacetal of U. S. Patent 2,310,943-Example 2, as a blue-green color former to produce layer ll. Layers 8 and II may be printed with blue light and color developed in a solution a described in Example III. The film shown in Fig. 3 is then fixed, bleached in an oxidizing bath as described in Example I, dried and printed with red light and developed in a solution of the following composition:

Example VIII A cellulose acetate film base I2 is coated with a gelatin dispersion of inert finely divided silver containing a green blind sensitizer as described in Middleton and Jennings U. S. Patent 2,270,378 and oxynaphthoic-p-lauryl anilide to form layer [3 on which is coated a gelatin layer M on which is coated a gelatin dispersion of inert finely divided silver erythrosine and 4,4-bis-(3"- phenylpyrazolonyl-l") biphenyl to form layer [5, a gelatin dispersion containing a yellow dye is next coated producing filter layer l6 and finally a gelatin dispersion of inert finely divided silver containing furoylacet-benzoylacetbenzidine forming layer H. The resulting film, shown in Fig. 4, i inert to light and when it is desired to use the same it is bleached after the manner described in Example I and dried and then exposed and processed after the manner described in U. S. Patent 2,186,234.

In place of the bleaching solutions described in. the above examples, one may use other types of solutions which will convert finely divided silver into developable silver salts. Additional suitable solutions include the following:

H2O ..ccs 1000 KBr grarns 20 NaCl do 25 Ka'Fe(CN) 6 do i 15 NazCOa do 15 H2O I ccs 1000 NHgBr grams 25 Brz cc 1 NHiBr grams 24 I2 dO .5 H2O ccs Similarly in place of the gelatin, one may substitute other binding agents such as agar-agar, polyglycuronic acid, hydrophilic cellulose derivatives, e. g., ethyl cellulose, cellulose acetate containing 20 to 25% of solubilizing groups such as acid phthalate groups, etc.

A wide Variety of optical sensitizing agents can be substituted for those described in the above examples. A large number of such agents are described in The Theory of the Photographic Process by Mees, pages 961-986 published by the Macmillan Co., N. Y. (1942) Similarly various types of color formers can be substituted for those described in the above examples. By color formers is meant th chemical compounds which couple with the oxidation products of primary aromatic amino developing agents formed during the development of silver salt images to produce quinoneimine or azomethine dyes. These compounds contain nuclei or color former components which have as theactive coupling groups a structure which may be represented by the general formula Where X is an HO radical or an RHN radical, where R is hydrogen, an alkyl or substituted alkyl group, e. g., methyl, ethyl, betachlorethyl, betahydroxyethyl, benzyl, etc., and n is 0 or 1. Thus X may be a primary or secondaryamine group. Such active coupling groups are found in reactive methylene dye intermediates and in aromatic hydroxyl and amino compounds and include reactive ethenol, aminoethenyl, 4-hydroxyand 4-amino 1,3-butadienyl groups. These groupsare found in phenols, naphthols, anilines, naphthylamines, acylacetamides, cyanoacetamides, betaketoesters, pyrazolones, N homophthylamines, coumaranones, indoxyls, thioindoxyls, etc.

The compounds of the above type should be chosen so that they are fast to diffusion in the hydrophilic colloid layers. This may be accomplished by means of groups of high molecular weight, polymeric groups, etc. Various types of suitable color formers are described in United States Patents 2,328,034, 2,365,206, and the patents referred to therein.

In place of the silver salts described in the examples one may substitute silver chloride, silver nitrate, silver phosphate, silver dichrom-ate, silver citrate, and silver fluoride or mixtures of such salts.

Similarly in. placeof the reducing agents described above there may be substituted other reducing agents, e. g., diphenylcarbazide, sodium hydrosulfite, sodium formaldehyde sulfoxylate, etc.

In a preferred aspect of the invention hydrophilic colloid color formers are used. Such color formers have the advantage that they serve as the binding agent for the inert silver and for the silver halides formed after bleaching in addition to contributing dye images upon color coupling development. Additional suitable agents of this type are described in United States Patents 2,178,- 612, 2,186,734, 2,307,399, 2,310,943, 2,320,422, 2,323,481, and in applications Serial Nos. 528,943, now U. S. Patent 2,397,865, 528,944, now U. S. Patent 2,423,460; 528,946, now U. S. Patent 2,415,381, and 528,947, now U. S. Patent 2,415,382, filed March 31, 1944. In this aspect of the invention additional hydrophilic colloids free from color former groups can be used.

The elements of this invention are obviously not limited to any one particular use. On the contrary, they are useful in various methods for producing photographic images in metallic silver and/or dyes. They can be used in camer as taking stocks or in printing apparatus as printing stocks. They can be used for producing sound tracks, key images, additional colors, etc. in special elements. They can serve the dual purpose of blocking layers and image forming layers.

The invention has many obvious advantages. The novel films have as a primary advantag an inertness to light. This means that they may be packed in more simplified containers and do not require handling in dark rooms until use. The coating operations may be carried out in ordinary light which is a decided economic advantage. Other film defects due to variations in environment would not show up in the inert layers of the novel elements hereof.

As many widely different embodiments of this invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not to be limited except as defined by the claims.

What is claimed is:

1. A light-insensitive liquefied photographic coating composition comprising a hydrophilic colloid which has uniformly dispersed therethrough finely divided, discrete particles of inert silver and an optical sensitizing dye said inert silver being the only silver atoms in said composition.

2. A light-insensitive liquefied photographic coating composition comprising a hydrophilic colloid which has uniformly dispersed therethrough finely divided, discrete particles of inert silver, an optical sensitizing dye and a color former said inert silver being the only silver atoms in said composition.

3. A light-insensitive liquefied photographic coating composition comprising a hydrophilic colloid-color-former which has as the active coupling group a structure of the general formula where X is a member taken from the group consisting of Ol-l and primary and secondary amino groups, said color former being capable of forming a dye taken from the group consisting of quinoneimine and azomethine dyes during the development of silver halide images which has uniformly dispersed therethrough finely divided,

discrete particles of inert silver and an optical sensitizing dye said inert silver being the only silver atoms in said composition.

4. A light-insensitive photographic element which is free from image records and comprises a support bearing at least one layer composed of a hydrophilic colloid which has uniformly dispersed therethrough finely divided, discrete particle of inert silver and an optical sensitizing dye.

5. A light-insensitive photographic element which is free from image records and comprises a support bearing at least one layer composed of a hydrophilic colloid which has uniformly dispersed therethrough finely divided, discrete particles of inert silver, an optical sensitizing dye and a color-former which has as the active coupling group a structure of the general formula X '1=t). (t=t11) where X is a member taken from the group consisting of OH and primary and secondary amino groups, said color former being capable of forming a dye taken from the group consisting of quinoneimine and azomethine dyes during the development of silver halide images.

6. A light-insensitive photographic element which is free from image records and comprises a support bearing at least one layer composed of a hydrophilic colloid-color-former which has as the active coupling group a structure of the general formula 3 Where X is a member taken from the group consisting of OH and primary and secondary amino groups, said color former being capable of forming a dye taken from the group consisting of quinoneimine and azomethine dyes during the development of silver halide images which has uniformly dispersed therethrough finely divided, discrete particles of inert silver and an optical sensitizing dye.

'7. A multilayer light-insensitive color film which is free from image records and comprises a film base bearing at least two hydrophilic layers containing an immobile color-former which has as the active coupling group a structure of the general formula where X is a member taken from the group consisting of OH and primary and secondary amino groups, said color former being capable of forming a dye taken from the group consisting of quinoneimine and azomethine dyes during the development of silver halide images and at least one layer composed of a hydrophilic colloid which has uniformly dispersed therethrough finely divided, discrete particles of inert silver and an optical sensitizing dye.

8. A multilayer color film. comprising a film base bearing at least two hydrophilic layers containing light-sensitive silver halides and an immobile color-former which has as the active coupling group a structure of the general formula sisting of -OH and primary and secondary amino groups, said color former being capable of forming a dye taken from the group consisting of quinoneimine and azomethine dyes during the development of silver halide images and at least one light-insensitive layer composed of a 9. A multilayer light-insensitive film which is free from image records and comprises a transparent film base bearing three layers each composed of a hydrophilic colloid which has uniformly dispersed therethrough finely divided, discrete particles of inert silver, an optical sensitizing dye and a color-former which has as the active coupling group a structure of the general formula diffusing and yielding a quinoneimine dye complementary in color to the utilized sensitivity of the respective layer.

ANDREW BRADSHAW JENNINGS. OTIS WILLARD MURRAY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,273,457 Capstaff July 23, 1918 1,954,452 Mannes et a1 Apr. 10, 1934 2,148,979 Dieterle Feb. 28, 1939 2,153,617 Eggert et a1. Apr. 11, 1939 2,159,280 Mannes et a1 May 23, 1939 2,186,054 Weaver Jan. 9, 1940 2,219,987 Gaspar Oct. 29, 1940 2,219,988 Gaspar Oct. 29, 1940 2,244,589 Yanket June 3, 1941 2,253,070 Evans Aug. 19, 1941 2,266,443 Schinzel Dec. 16, 1941 2,295,013 Schinzel Sept. 8, 1942 2,319,369 Sease et a1 May 18, 1943 2,320,005 Michaelis May 25, 1943 2,415,381 Woodward Feb. 4, 1947 2,463,838 Wilson Mar. 8, 1949 FOREIGN PATENTS Number Country Date 488,548 Great Britain July 7, 1938 

1. A LIGHT-SENSITIVE LIQUEFIED PHOTOGRAPHIC COATING COMPOSITION COMPRISING A HYDROPHILIC COLLOID WHICH HAS UNIFORMLY DISPERSED THERETHROUGH FINELY DIVIDED, DISCRETE PARTICLES OF INERT SILVER AND AN OPTICAL SENSITIZING DYE SAID INERT SILVER BEING THE ONLY SILVER ATOMS IN SAID COMPOSITION. 